A. E. Woodard

THE EFFECT AND AFTER-EFFECT OF VARIED EXPOSURE TO LIGHT ON CHICKEN DEVELOPMENT

The present experiments were designed to determine the effects of:a. Total daily amount of lightb. Intensity of lightc. Frequency of light intervalson the growth and development of Leghorn chickens.a. Total daily amount of light exposures: The first test dealt with the effect of supplementing natural light with continuous light. Continuous light improved body weight of all birds and testes size of males at 7 weeks, but impaired feather development. Continuous lighting delayed sexual maturity of pullets, and growth in both sexes was retarded until they reached 20 weeks of age.In the second experiment under suboptimal light intensities, light exposure has no effect on body size after 12 weeks of age. Rate of sexual development was increased by larger daily exposures to light. These effects were more pronounced when treatments were applied to pullets over 90 days old than during earlier stages of development.b. Intensity of light: Three light intensities were applied to growing birds: 0.0-0.4 foot-candles, 0...